The invention relates to a resilient central bearing for a propeller shaft such as used on motor vehicle drives. The bearing has a roller bearing held in a housing which is provided with a bracket for being secured to the vehicle body.
Because of unbalanced inertia forces and moments of the rotating engine parts, unavoidable rotary vibrations of the engine/gearbox system, and resilient balancing movements of the drive assembly relative to the vehicle the propeller shafts in the driveline of a motor vehicle are subject to permanent loads as a result of rotational and bending vibrations. The vibrations in the resonance range of the driveshaft exhibit particularly high amplitudes, as a result of which the bearing parts and joints are subjected to particularly high loads. Furthermore, the vibrations lead to an interfering noise in the passenger compartment of the vehicle.
Both in the case of divided shafts with an intermediate joint, particularly in the hub of the intermediate joint, and with the increasingly popular undivided shafts made of, for example, a fiber composite material, it is desirable to provide central bearings of the above-mentioned type for reducing the bending vibrations.
It has been a common practice to fit the roller bearing on the shaft so as to be secured axially and radially, with the housing of the bearing being provided with resilient elements, between the outer bearing race and the bracket. The resilient elements are often in the form of an annular boot made of elastomer. Such a housing utilizing hydraulic damping chambers is known from DE 39 31 387.
With previous central bearings, fitting the roller bearing on the tubular shaft has been problematical especially if the latter consists of a fiber composite material which may not be suitable for providing a bearing seat of the conventional type.